1. service mysqld stop
2. vi /etc/my.cnf
3.在[mysqld]片段中开始新增skip-grant-tables，保存退出vi
4.service mysqld start
5.mysql -u root mysql，进入mysql
6.mysql>use mysql;
7.mysql>update user set password=PASSWORD(’111111’) where user=’root’;
如果找不到password字段，是因为mysql5.7版本password字段改成了authentication_string，用以下语句即可
mysql>update user set authentication_string=password('111111') where user='root' ;
7.mysql>flush privileges;
8.mysql>quit;
9.vi /etc/my.cnf，删除skip-grant-tables，保存退出vi
10.service mysqld start
11.mysql -u root -p，此时输入密码即可。